Owing to the advancement of industry and technology, the quality of human life has been greatly enhanced. Yet, at the same time, the environment has become badly polluted during this process of advancement. Among these various environmental problems which have arisen, air pollution has become one of the most serious problems. Several particular particles in the air, such as organic components, NOx, SOx, CO, and even smoke and odors have been proven to be harmful to plants, animals, humans, property and the general quality of life.
It has been verified in recent years that polluting emissions discharged from factories and automobiles, or fumes or smoke produced in the chemical, pharmaceutical and surface coating industries, can cause diseases such as lung cancer, emphysema and asthma. Moreover, such polluting particles also often cause slow poisoning, headaches, insomnia, eyeaches, etc.
As a result, great efforts are being made by governments and private industry both to prevent air pollution, and a great deal of equipment has been specifically developed in recent years to remove such polluting particles from the air. For example, settling chambers, commonly used to remove very large airborne particles; cyclone collectors, widely used to remove medium size particles; bag filters, used to collect dust; wet collectors, for eliminating large sized particles; electrostatic precipitators, for removing microparticles; incineration, for removing gas pollutants; absorption applications, using materials such as activated carbon to catch pollutants; and gas-scrubbers, used to clean gaseous type pollution. However, with respect to extremely fine dust and suspended solids in the air, such as fumes, cigarette smoke composed of nicotine, tar and ammonia, no effective and economic method has yet been developed to remove such pollutant particles scattered in the air.